'Guard' in the Bible

Shallum son of Kore, son of Ebiasaph, son of Korah and his relatives from his ancestral household, the Korahites, were assigned to guard the thresholds of the tent. Their ancestors had been assigned to the Lord’s camp as guardians of the entrance.

They spent the night in the vicinity of God’s temple, because they had guard duty and were in charge of opening it every morning.